JPH07302513A - Multilayered insulated electric wire and transformer using it - Google Patents

Abstract

PURPOSE:To provide a multilayered insulated electric wire whose insulating layers are formed by extrusion coating and have excellent solderability, interlayer peeling properties, heat resistance, electrically insulating properties, and coiling processibility and provide a transformer using the electric wire. CONSTITUTION:The first and the third insulating layers from the conductor side are layers formed by extrusion coating of thermally plastic polyamide resin or a resin mixture consisting of mainly thermally plastic polyamide resin. The second insulating layer is a layer formed by extrusion coating of a resin mixture consisting of 100 pts. by wt. of thermally plastic linear polyester resin produced by binding aliphatic alcohol component and an acid component and 5-40 pts. by wt. of ethylene-based copolymer having carboxylic acid or carboxylic acid metal salt as a side chain. Or, the second layer is an extrusion coating layer the whole or a part of which consists of mainly thermally plastic linear polyester resin or an extrusion coating layer the whole or a part of which consists of a resin mixture containing 100 pts. by wt. of thermally plastic linear polyester resin and not more than 50 pts. by wt. of ethylene-based copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has three or four insulating layers.
Regarding the multi-layer insulated wire having more than one layer and the transformer using the same, more specifically, the peelability between the insulating layers for identifying the layers of each insulating layer is excellent, and the insulating layer becomes Since it can be removed in a short time and solder can be attached to the conductor, it has excellent soldering characteristics, and also has excellent coil processability, which is useful as a winding wire or lead wire for transformers incorporated in electrical and electronic equipment. And a transformer using the same.

[0002]

2. Description of the Related Art The structure of a transformer is based on the IEC standard (Internat
ional Electrotechnical Communication Standard) Pu
b. 950,65, etc. That is, in these standards, the enamel coating that covers the conductor in the winding is not recognized as an insulating layer, and at least three insulating layers are formed between the primary winding and the secondary winding, or The thickness is 0.4mm or more, the creepage distance between the primary winding and the secondary winding depends on the applied voltage, but it is 5mm or more, and when 3000V is applied to the primary side and the secondary side. It is specified that it can withstand more than 1 minute.

For this reason, in transformers that currently occupy mainstream seats, for example, a bobbin with a collar is fitted in a ferrite core, and insulating barriers for securing a creepage distance are arranged at both ends of the peripheral surface of the bobbin. After winding the enamel-coated primary winding in this state, at least three layers of insulating tape are wound on this primary winding, and an insulating barrier for securing a creepage distance is further provided on this insulating tape layer. After arranging, it has a structure in which a secondary winding also coated with enamel is wound.

By the way, in recent years, a transformer having a structure not including an insulating barrier or an insulating tape layer has begun to appear in place of the transformer having the above structure. Compared with the conventional structure, this transformer has the advantages that the space factor of the winding is smaller, so the whole size can be made smaller, and the work of winding the insulating tape can be omitted. There is.

When manufacturing the transformer having this novel structure, at least three insulating layers are formed on the outer circumference of one or both conductors in the primary winding and the secondary winding used, and It is necessary that the respective insulating layers can be separated from each other in relation to the above-mentioned IEC standard. For such a winding, first, an insulating tape is wound around the conductor to form a first insulating layer,
On top of that, an insulating tape is wrapped around to form a second insulating layer,
It is known that an insulating layer having a three-layer structure is formed in which a third insulating layer is sequentially formed and layers are separated from each other. Further, there is known a winding in which a fluorine-based resin is sequentially extrusion-coated on the outer circumference of a conductor which is enamel-coated with polyurethane, and an extrusion-coated layer having a three-layer structure is used as an insulating layer as a whole (Actual Publication No. 3-56112). Issue).

[0006]

However, in the case of the former winding, the winding work of the insulating tape is unavoidable, so that the productivity is remarkably lowered, and therefore the manufacturing cost is increased. Also, in the case of the latter winding, since the insulating layer is formed of a fluorine-based resin, it has the advantage of good heat resistance and delamination, but conversely, the adhesion between layers is Since it is bad, it is difficult to secure reliability as an insulated wire.

Furthermore, in the case of this insulating layer, it cannot be removed even by dipping it in a solder bath. Therefore, for example, in the case of terminal processing when connecting an insulated wire to a lead pin of a component, the insulating layer of the terminal is reliable. There is a problem that it has to be peeled off beforehand by a mechanical means having low property. In order to solve such a problem, the present inventors formed the first insulating layer and the second insulating layer both as extruded coating layers of a polyester resin, and the outermost third insulating layer. Has already applied for a three-layer insulated wire in which the polyamide resin is formed (Japanese Patent Application No. 5-2
70484).

However, the three-layer insulated wire has the following complaints. That is, since the polyester-based resin is relatively soft, when the electric wire is coiled, it receives a compressive force based on the winding tension applied to the outermost layer.
The first and first insulating layers (polyester resin layers) are slightly compressed and deformed in the thickness direction. When the coil manufactured as described above is energized, the polyester resin is softened by the resistance heat generated from the conductor, and the winding tension is always acting. Therefore, the second and first insulating layers The compressive deformation in (1) further progresses, the thickness of the insulating layer becomes thin, and eventually the insulating layer is crushed as a whole. If such a state is reached, the electrical insulating property of the insulating layer deteriorates.

Further, since the first insulating layer and the second insulating layer are both made of polyester resin, they adhere to each other during the softening process, making it difficult to distinguish between the layers.
INDUSTRIAL APPLICABILITY The present invention solves the above-mentioned problems in the conventional three-layer insulated wire or the multilayer insulated wire and satisfies the IEC standard, and the heat resistance and softening resistance of the insulating layer are excellent, and the insulating layer is It is an object of the present invention to provide a multilayer insulated wire which can be made thin and which can be expected to have a good delamination property of an insulating layer even after being used for a long time, and a transformer using the same.

[0010]

In order to achieve the above-mentioned object, in the present invention, in a multilayer insulated wire comprising a conductor and three or more insulating layers covering the conductor, the first layer from the conductor side is provided. And each of the third insulating layer is an extrusion coating layer of a thermoplastic polyamide resin or a resin mixture containing a thermoplastic polyamide resin as a main component, and 2
The insulating layer of the first layer has (a) a carboxylic acid or a metal salt of a carboxylic acid in a side chain with respect to 100 parts by weight of a thermoplastic linear polyester resin formed by combining an aliphatic alcohol component and an acid component. Extrusion coating layer (hereinafter referred to as extrusion coating layer a) of a resin mixture prepared by blending 5 to 40 parts by weight of an ethylene copolymer, (b) all or part of an alicyclic alcohol component and an acid component. Extrusion coating layer (hereinafter referred to as extrusion coating layer b) containing a thermoplastic linear polyester resin as a main component formed by bonding, or (c) an alicyclic alcohol component and an acid component, wholly or partially, Extrusion of a resin mixture prepared by mixing 50 parts by weight or less of an ethylene copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain with 100 parts by weight of a thermoplastic linear polyester resin formed by bonding. Kutsugaeso (hereinafter, referred to as extruded covering layer c) is a multilayer insulated wire which is characterized in that either are provided.

In the multi-layer insulated wire of the present invention, the surface of the conductor is 3
It is covered with at least one insulating layer. Of these insulating layers, it is essential that the first, second, and third insulating layers counted from the conductor have the structure described later. And on the third insulating layer, the fourth, fifth ...
, And an arbitrary number of insulating layers may be formed. First, the first insulating layer in the multilayer insulated wire of the present invention is
It is an extrusion coating layer of a thermoplastic polyamide resin or a resin mixture containing it as a main component.

The first insulating layer has a good adhesion to the conductor, a mechanical strength higher than that of the polyester resin, and a high softening temperature. Therefore, due to the winding tension during coil processing and the heat generated by the conductor during coil use,
Even if the crushing phenomenon occurs in the third insulating layer, the deformability of the first insulating layer is small, so that the crushing phenomenon is effectively prevented from spreading to the conductors, and the insulation characteristics are not deteriorated. Suppressed.

As the thermoplastic polyamide resin forming the first insulating layer, for example, 4-nylon, 6-nylon, 10-nylon, 11-nylon, 12-nylon, 4,6-nylon, 6, 6-nylon, 6,10
-Nylon, 6,12-nylon, or copolymerized nylon thereof (all are trade names manufactured by DuPont). Each of these may be used alone, or two or more of them may be appropriately mixed and used.

Of these thermoplastic polyamide resins, 4,6-nylon has a melting point of 2 compared to other nylons.
It has a high heat resistance of about 0 to 30 ° C., about 290 ° C., so that even when an insulating layer having a thickness of about 60 μm is used, thermal deformation is unlikely to occur when the coil is used.
It is suitable as a material for the second insulating layer. In addition to the above-mentioned thermoplastic polyamide resin, for example, one kind or two kinds of ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, thermoplastic linear polyester resin, polyurethane resin, polycarbonate resin, etc. The above may be mixed as a modified resin.

In this case, if the mixing ratio of the above modified resin to the thermoplastic polyamide resin is too high, the heat resistance and softening resistance of the insulating layer deteriorate, and the winding tension during coil processing and conductor heat generation during current application. As a result, the insulating layer is apt to be deformed, and when it is too small, the adhesion between the insulating layer and the conductor is deteriorated, and so-called sheath omission may occur. Therefore, the mixing ratio is preferably set to 5 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic polyamide resin. It is particularly preferably 10 to 30 parts by weight.

Of these miscible resins, thermoplastic linear polyester resins are preferred. As this thermoplastic linear polyester resin, a resin obtained by an ester reaction of an aromatic dicarboxylic acid or a dicarboxylic acid partially substituted with an aliphatic dicarboxylic acid and an aliphatic diol is used. For example, polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene naphthalate resin, polycyclohexane methylene terephthalate resin (PCT) and the like can be mentioned as typical examples.

Besides the thermoplastic linear polyester resin, polycarbonate resin, polyurethane resin, etc. are also suitable as the modified resin. These may be used alone or in an appropriate mixture of two or more.
Next, the second insulating layer will be described. The second insulating layer is formed by any one of the extrusion coating layer a, the extrusion coating layer b, and the extrusion coating layer c described above.

The resin mixture forming the extrusion coating layer a contains a thermoplastic linear polyester resin described below and an ethylene copolymer as essential components. Among them, the thermoplastic linear polyester resin is preferably a resin obtained by an ester reaction of an aromatic dicarboxylic acid or a dicarboxylic acid, a part of which is substituted with an aliphatic dicarboxylic acid, and an aliphatic diol. For example, polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PB)
Typical examples include T) and polyethylene naphthalate resin.

Examples of the aromatic dicarboxylic acid used during the synthesis of the thermoplastic linear polyester resin include terephthalic acid, isophthalic acid, terephthaldicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether carboxylic acid and methyl terephthalate. Acid, methyl isophthalic acid, etc. can be mentioned. Of these, terephthalic acid is particularly preferable.

Examples of the aliphatic dicarboxylic acid substituting a part of the aromatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid and the like. The amount of substitution of these aliphatic dicarboxylic acids is the same as that of aromatic dicarboxylic acids.
It is preferably less than 0 mol%, particularly 20 mol%.
It is preferably less than. On the other hand, examples of the aliphatic diol used in the ester reaction include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexanediol and decanediol. Of these, ethylene glycol and tetramethyl glycol are preferable. Moreover, as the aliphatic diol, a part thereof may be oxyglycol such as polyethylene glycol or polytetramethylene glycol.

The other essential component of the resin mixture forming the extrusion coating layer a is, for example, an ethylene-based copolymer in which a carboxylic acid or a metal salt of a carboxylic acid is bonded to the side chain of polyethylene. This ethylene copolymer functions to suppress crystallization of the thermoplastic linear polyester resin described above, thereby preventing or forming cracks in the extrusion coating layer due to the load applied during coil processing. It suppresses deterioration of the electrical characteristics of the insulating layer with time.

The carboxylic acid to be bonded is, for example,
Examples thereof include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and phthalic acid. Examples of metal salts thereof include Zn and Na. , K, Mg and the like. As such an ethylene-based copolymer, for example, a part of the carboxylic acid of the ethylene-methacrylic acid copolymer is made into a metal salt, and a resin generally called an ionomer (for example, Himilan; trade name, Mitsui Polychemical Co., Ltd.). , Ethylene-acrylic acid copolymer (for example, EAA; trade name, manufactured by Dow Chemical Co., Ltd.), ethylene-based graft polymer having a carboxylic acid in a side chain (for example, Admer; trade name, Mitsui Petrochemical Industry Co., Ltd. ) Made).

In this resin mixture, the blending ratio of the thermoplastic linear polyester resin and the ethylene copolymer is
The latter is set in a range of 5 to 40 parts by weight with respect to the former 100 parts by weight. When the compounding amount of the latter is less than 5 parts by weight, there is no problem in heat resistance of the formed insulating layer, but the effect of suppressing crystallization of the thermoplastic linear polyester resin becomes small, and therefore the insulating layer of the insulating layer is not formed during coil processing. The so-called crazing phenomenon in which minute cracks occur on the surface frequently occurs. In addition, the deterioration of the insulating layer with time progresses, causing a large decrease in the dielectric breakdown voltage. On the other hand, the compounding amount is 40
When the amount is more than the weight part, the heat resistance of the insulating layer is significantly lowered. The preferable mixing ratio of both is 100 parts by weight of the former and 7 to 25 parts by weight of the latter.

Next, the material for forming the extrusion coating layer b is
The thermoplastic linear polyester resin is as follows. That is, a thermoplastic linear polyester resin formed by combining an alcohol component, which is cyclohexanedimethanol of an alicyclic alcohol, and an acid component, specifically, a polycyclohexanedimethylene terephthalate resin. (PCT) can be mentioned. This resin has heat resistance superior to that of PET described above.

Examples of such a PCT resin include EKTAR-DN, EKTAR-DA, and EKTAR.
-GN (trade name, manufactured by Toray Industries, Inc.) can be preferably used. Considering that the decrease in the dielectric breakdown voltage due to the deterioration of the insulating layer with time is suppressed, a modified resin such as a polycarbonate resin or a polyurethane resin is used in an amount of 10 to 100 parts by weight of the thermoplastic linear polyester resin. It is preferable to add 100 parts by weight. Note that it is preferable to add a polyamide resin in order to maintain appropriate peelability from the first and third insulating layers.

The resin mixture forming the extrusion coating layer c is a resin mixture of the above-mentioned PCT resin and the like and an ethylene copolymer which is an essential component in the resin mixture used for forming the extrusion coating layer a. Is. In this resin mixture, P
The compounding ratio of the CT-based resin and the ethylene-based copolymer is set to 100 parts by weight of the former and 50 parts by weight or less of the latter.

When the amount of the ethylene copolymer is more than 50 parts by weight, the excellent heat resistance of the PCT resin is deteriorated, and the heat resistance of the formed insulating layer becomes a problem. The preferable blending ratio of both is 5 to 30 parts by weight of the latter with respect to 100 parts by weight of the former. The third insulating layer in the multilayer insulated wire of the present invention is formed of a thermoplastic polyamide resin or a resin mixture containing the thermoplastic polyamide resin as a main component. This third insulating layer has a relatively small surface friction coefficient and excellent mechanical strength, so that damage such as cracking in the outermost layer during coil processing of the electric wire can be minimized. it can. In addition, since the adhesiveness to the second insulating layer (polyester resin layer) is low, even if the outermost layer is damaged, the damage is prevented from spreading to the second insulating layer. As a result, it is possible to prevent deterioration of the insulation characteristics after the coil processing.

Further, the third insulating layer is formed by using the extruded coating layer a or the extruded coating layer c in which the second insulating layer contains a small amount of polyethylene copolymer, or by using cyclohexanediene. When it is formed of the extruded coating layer b made of a PCT resin in which the amount of methanol used is small, it functions to mitigate the deterioration of the second insulating layer with time. Examples of the thermoplastic polyamide resin forming the third insulating layer include 4-nylon, 6-nylon, 10-nylon, 11-nylon, 12-nylon, 4,6-nylon, 6,6-nylon. , 6,10-nylon, 6,
12-nylon or copolymer nylon thereof (all are trade names manufactured by DuPont) can be mentioned.
Particularly, 4,6-nylon is preferable because it has excellent heat resistance.

In addition to these thermoplastic polyamide resins, for example, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, polyethylene, the above-mentioned thermoplastic linear polyester resin, polyurethane resin, polycarbonate resin, etc. You may mix 1 type (s) or 2 or more types. In this case, the mixing ratio of polyamide resin 10
It is preferably 3 to 50 parts by weight with respect to 0 parts by weight.

In the multi-layer insulated wire of the present invention, the outer periphery of the conductor is extrusion-coated with the thermoplastic polyamide resin for the first layer or a resin mixture containing the same as the main component to form the first insulating layer of a desired thickness. Then, the outer periphery of the first insulating layer is extrusion-coated with the above-mentioned thermoplastic linear polyester resin for the second layer or a resin mixture containing the same as the main component, and the insulation of the second layer having a desired thickness is obtained. A third layer of the insulating layer having a desired thickness by forming a layer on the outer periphery of the second insulating layer by extrusion coating a thermoplastic polyamide resin for the third layer or a resin mixture containing the thermoplastic polyamide resin as a main component. Is manufactured by forming.

At this time, the resin used for each extrusion coating of the first layer and the third layer may be a thermoplastic polyamide resin or a resin mixture containing it as a main component, and may be the same kind or different kinds. Good. In addition, in the multilayer insulated wire of the present invention, when forming the first and third insulating layers,
A resin mixture containing 100 parts by weight of 6-nylon or 4,6-nylon and 20 parts by weight or less of another admixture resin was used, and 60 mol of cyclohexane dimethanol was used to form the second insulating layer. % Of PCT-based resin substituted by 20% by weight or less of other admixture resin is used, the heat resistance class of the electric wire is IEC Pub. 172 class E level (1
It can be improved from 20 ° C.) to the type B level (130 ° C.).

By using the above-mentioned multilayer insulated wire of the present invention, the transformer of the present invention can be obtained. In the transformer of the present invention, the multilayer insulated wire of the present invention is used for both or either of the primary winding and the secondary winding. In that case, it is not necessary to interpose an insulating tape between the primary winding and the secondary winding, but it may be interposed.

[0033]

In the multi-layer insulated wire according to the first aspect of the present invention, since each insulating layer is formed by extrusion coating of resin, the productivity at the time of manufacture becomes very high. Further, since the insulating layers are in a state in which different materials are in contact with each other, the inter-layer peeling property is good. Then, when the terminal is processed, the soldering can be directly performed.

Since the crush resistance of the first and third insulating layers is excellent, the crushing phenomenon of the insulating layer due to the winding tension during coil processing and the heat generation of the conductor when the coil is used spreads to the conductor surface. Will not do. Since the second insulating layer is formed of the extruded coating layer a, the extruded coating layer b, or the extruded coating layer c, the heat resistance is good, and the PET resin and the PCT resin are not crystallized. It is suppressed, and the breakdown voltage of the insulating layer is unlikely to drop.

Further, since the third insulating layer is made of thermoplastic polyamide resin or a resin mixture containing it as a main component, the friction coefficient of the outer surface becomes small, and the wire surface is damaged during coil processing. Is suppressed. In the multilayer insulated wire according to claim 2, since the second insulating layer is formed by the extruded coating layer b or the extruded coating layer c using cyclohexanedimethanol as the alicyclic alcohol component, heat resistance is improved. .

In the multi-layer insulated wire according to claim 3, since the first and / or third insulating layers are made of 4,6-nylon or a resin mixture containing the same as the main component, heat resistance is further improved. It is possible to improve the thickness of the insulating layer to a thickness of about 60 μm. The multi-layer insulated wire according to claim 4,
Since the first insulating layer is made of a resin mixture made by blending a thermoplastic polyamide resin with a modified resin, the adhesion between the first insulating layer and the conductor is proper, so-called sheath omission, etc. Will not happen.

Since the transformer of claim 5 is manufactured by using the multilayer insulated wire of claims 1 to 4, it is a matter of course that the transformer satisfies the IEC standard. It has a small product ratio and can be miniaturized.

[0038]

Examples Examples 1 to 6 and Comparative Examples 1 to 5 The components shown in Table 1 were kneaded in the indicated proportions (parts by weight) to prepare a resin mixture for each extrusion coating layer. An annealed copper wire having a wire diameter of 0.6 mm is prepared as a conductor, and the outer periphery thereof is extrusion-coated with the above-mentioned resin mixture to form a first extrusion coating layer with the indicated thickness, and then a second extrusion coating. A layer was formed, and the outer periphery of the second layer was extrusion-coated with the above resin mixture to produce a three-layer insulated wire.

[0039]

[Table 1]

With respect to the above 11 kinds of three-layer insulated wires, various characteristics were measured with the following specifications. Solderability: The temperature of the end of the wire about 40mm is 400 ℃
Immerse in the molten solder, and measure the time (seconds) until the solder adheres to the immersed 30 mm portion. The shorter this time is, the better the solderability is.

Electrical insulation: For each of the two-layer coating and three-layer coating electric wires immediately after production, according to the two-strand method specified in JISC3003, and using a bare copper wire on one side, the dielectric breakdown voltage at that time is measured. Measurement. The electric wire coated with three layers was left in the atmosphere for one year, and then the dielectric breakdown voltage was measured by the same method as above to examine the change over time in the electrical insulation property.

Heat resistance: JISC for 3-layer coated wire and bare copper wire
Twist two in accordance with 3003, in that state, the temperature 20
After performing heat treatment at 0 ° C. and 230 ° C. for 1 week, the dielectric breakdown voltage was measured. The larger this value is, the better the heat resistance is. In addition, it can be evaluated that the deterioration of the dielectric breakdown voltage is extremely small in the case of the type B level evaluated by the heat treatment at 230 ° C. for one week.

Crazing resistance: After the electric wire was left in the atmosphere for 6 months, the electric wire was mechanically wound around a coil winding frame having a diameter of 12 mm, and it was observed whether crazing occurred on the surface of the electric wire. Delamination: After incising the insulating layer for about 50 cm in the longitudinal direction with a cutter knife, also one in the circumferential direction of the wire,
Make a notch along the entire circumference, fix one end of the wire to the twister, sandwich the other end in the chuck of the twister to hold the wire straight, and rotate the chuck in this state to center the wire in the longitudinal direction. As a result, the number of rotations at which the three insulating layers were separated from each other was examined. Note that the peeling is performed at the time when a part of the coating film of the cut portion in the circumferential direction is peeled off. The smaller the number of rotations, the better the delamination property.

Coil workability: A conductive square core having a square cross section with a side of 7 mm is used to wind a wire in an aligned manner (50 turns) while applying a tension of 6 kg using a processing machine, and between the wire and the square core. Measures the time until dielectric breakdown occurs when a voltage of 3000 V is applied to. This test has 10 coils each
The results are evaluated by the average value. The longer this time is, the less the insulating layer is damaged during coil processing, that is, the better the coil processability is. The guide nozzle used had a tip hole diameter larger than the outer diameter of the electric wire by 0.05 mm, and the linear velocity was set to 20 m / min.

Softening resistance: According to the crossing method specified in JISC3003, the short circuit temperature was measured when the load was 600 g and 3 kg. The higher this value is, the better the softening resistance of the insulating layer is, which means that the crushing phenomenon is hard to occur.

[0046]

[Table 2]

From the results shown in Table 2, the following becomes clear. 1) As is clear from the results of the softening resistance, the three-layer insulated wires of the examples all have a small difference in short-circuit temperature between a load of 600 g and 3 kg, and the insulation layer due to conductor heat generation and winding tension when the coil is used. Has excellent resistance to crushing action. 2) The three-layer insulated wire of Examples 1 and 2 in which the second layer was formed of a resin mixture containing an ethylene copolymer having a carboxylic acid or the like in the side chain (hereinafter referred to as a modifier) and a thermoplastic polyester resin. Has particularly excellent soldering characteristics and other characteristics.

3) The three-layer insulated wire of Examples 3 and 4 in which the second layer was formed of a mixture of PCT resin and the first layer and the third layer were made of 4,6-nylon was 230 The heat resistance evaluated at ℃ is very excellent, and the total thickness of the insulating layer is 60
It has excellent characteristics even if it is thinned to less than μm. 4) In the three-layer insulated wires of Examples 5 and 6 in which the second layer was formed of a mixture of PCT-based resins, the thickness of the entire insulating layer was 60 μm.
Even though it is thin, the properties such as heat resistance and solderability are well balanced.

5) Comparative Example 1 in which the first and second layers were formed by using the thermoplastic polyester resin alone without blending the above modifier.
The insulated wire has a remarkable change in characteristics over time. 6) On the other hand, the insulated wire of Comparative Example 2 in which the second layer is formed of the resin mixture containing the modifier in an excess amount (60 parts by weight) has poor heat resistance. 7) In Comparative Example 3, since the second layer and the third layer are formed of the thermoplastic polyester resin containing the modifier,
Poor delamination. Further, since the third layer is not formed of the thermoplastic polyamide resin, the surface slipperiness is insufficient and the coil processability is poor.

8) The insulated wire of Comparative Example 4 in which a film is wound to form an insulating layer cannot be soldered, has a low dielectric breakdown voltage, and has poor insulation characteristics. Further, the result of coil workability is also poor. 9) In the case of the three-layer insulated wire of Comparative Example 5 in which the insulating layer is formed of Teflon resin, it has excellent heat resistance but cannot be soldered, and the interlayer peeling property is 8 times, resulting in poor interlayer adhesion. Too much.

[0051]

As is apparent from the above description, claim 1
The multi-layer insulated wire of (1) has a very high productivity and a good delamination property. Then, when the terminal is processed, the soldering can be directly performed. Furthermore, the crushing phenomenon of the insulating layer due to the winding tension during coil processing and the heat generation of the conductor during use of the coil does not spread to the conductor surface. Then, the dielectric breakdown voltage of the insulating layer is unlikely to decrease with time. In addition, the coefficient of friction of the outer surface is small, and the electric wire surface is prevented from being damaged during coil processing.

In the multi-layer insulated wire of claim 2, since cyclohexanedimethanol is used as the alicyclic alcohol component, heat resistance is improved. In the multilayer insulated wire according to claim 3, the heat resistance is further improved, and the thickness of the entire insulating layer is 60 μm.
It is possible to reduce the wall thickness to a certain degree. Since the multilayer insulated wire according to claim 4 uses a resin mixture formed by blending a thermoplastic polyamide resin with a modified resin, the adhesion between the first insulating layer and the conductor is appropriate, and so-called sheath loss, etc. Is less likely to occur.

These multi-layer insulated wires are useful as a winding wire or a lead wire of a transformer having a new structure satisfying the IEC standard. The transformer according to the fifth aspect satisfies the IEC standard, and the insulating tape is eliminated, so that the space factor of the winding is small and the transformer can be miniaturized. Further, the insulating property is excellent, and its deterioration with time is small.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01F 27/32 Z // (C08L 67/02 23:26) (72) Inventor Nobuyuki Nakamura Tokyo 2-6-1, Marunouchi, Chiyoda-ku Furukawa Electric Co., Ltd.

Claims (5)

[Claims] 1. In a multi-layer insulated wire comprising a conductor and three or more insulating layers covering the conductor, the first insulating layer and the third insulating layer from the conductor side are each made of a thermoplastic polyamide resin or a heat insulating material. The second insulating layer is an extruded coating layer of a resin mixture containing a plastic polyamide resin as a main component, and the second insulating layer is (a) a thermoplastic linear chain formed by combining an aliphatic alcohol component and an acid component. An extrusion coating layer of a resin mixture comprising 5 to 40 parts by weight of an ethylene copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain, based on 100 parts by weight of a polyester resin, (b) all or one An extruded coating layer whose main part is a thermoplastic linear polyester resin formed by combining an alicyclic alcohol component and an acid component, or (c) an alicyclic alcohol component and an acid. component Resin blend prepared by blending 50 parts by weight or less of an ethylene-based copolymer having a carboxylic acid or a metal salt of a carboxylic acid in a side chain with 100 parts by weight of a thermoplastic linear polyester resin formed by combining The extruded coating layer of any one of 1. 2. The multilayer insulated wire according to claim 1, wherein the alicyclic alcohol component is cyclohexanedimethanol. 3. The multilayer insulated wire according to claim 1, wherein the first and / or third insulating layers are made of 4,6-nylon or a resin mixture containing 4,6-nylon as a main component. 4. The extrusion coating layer of a resin mixture, wherein the first insulating layer is a thermoplastic polyamide resin mixed with a thermoplastic linear polyester resin, a polycarbonate resin, or a polyurethane resin. Multi-layer insulated wire. 5. A transformer using any one of the multilayer insulated wires according to claim 1, 2, 3 or 4.